Process of making grain etchings



o AnL s W. SAALBUBG, or NEW YORK, N. Y., .ASSIGN'OR :TO- THEPRISMATONE 001,,- INc.,--oF vnw YORK, N. Y., A oortroaa'rron OF'NEW YORK. I

. ;gnocEss or MAKING GRAIN: memes lllo Prawing,

T0 all whom it m a y concern:

, Be it known that-I, CHARLEs WQ' 'SA AL- BURG, a citizen-ofthe United State s,'residing at New York city, in the county of New York and State of New-York, have invented a certain new anduseful Improvement in Processes of Making Grain Etchings, of whichthe following is a specification, This invention relates. to a process of making grain etcliingslin rotogravure'printing, and more specifically'toa process of making grain etchingson metal cylinders wherein a plurality of grains are made. f

In prior methods of providing suitable grains on metal-licrolls in the rotary photogravure printing art, diflicultyhas beenleirperienced in obtaining a full range of tints, .for either the light tintslor the heavy tones have suffered, and good Mrds'ufiicien't depths have not been obtained. In such processes the acid usedfor etching would eat through the sensitized film so rapidly that a proper grain, a cleanliness of tone, and an even and deep etching could not be obtained.

This invention has as an object the provision of processes for etching in rotogravure art, whereby perfect tones and a full range of tints may be attained. It also has for an object the securing of deeper printed depths, and also the securing of even and deep etchings with cleanliness of tones. A further object is to devise such a process which will be simple and comparatively inexpensive in operation and very eflicient from a technical standpoint.

The invention accordingly broadly comprises a process of making grain etchings comprising depositing a plurality of grains on a roll in conjunction with a carbon or similar print. More specifically stated, it comprises suchv processes in which the several grains may be of varying degrees'of fineness and quality.

Although the invention may be carried out in various forms and receive various embodiments, the following described method constitutes a preferred embodiment.

A grain is deposited on a copper or similar roll by spraying thereon asphaltum or equivalent material, and a plain, unscreened sensitized carbon print is placed over the grain to adhere thereto and is then dried. The paper backing is stripped off and the soluble gelatine washed away in the usual manner and the roll is then dried.

Specificationof Letters Patent. wy t n t d 125 21,1 22, Ap iilieation fileil gFehruary 15, 1921. Ser ial 11 445492;

A second grain is now deposited onthe carbon" print with a I 'gum' solution of any kind, but, for example, gum mastic dissolved lnturpentineto the consistency of a cream,

a is "i g o t ie? O top- 2i t s second grain the secondcarbon printissecured, whi'chtpr'int has been printed overa fine grainedjscreen. This second print, of

course, containsno' image exce t th t;oja

screenin order to provide this type of grain. Itis treated in the usual manner to fix the hardened gelatine tissue pro rly upon the roll as in'jthe ca'se of the: other above mentioned print. Q.

. 3 There] are 'thus gu eriape ea alias different grains, namely', the first grainfof asphaltum, the second grain of gum solution, and third grain consisting" of the screened carbon pg'ijnt. These grains are securely held in" place by 'thisprocess and provide a thick grain so that depth 'andgood printing qualities may be developed and a full range of tints and perfect tones may result. The

' grains need not be of the same qualities or degrees of fineness, so that it will be possible to obtain fine differences in the qualities of the etching by properly adjusting the nature and properties of each grain used.

It will be seen by the above described process, that the usual method of exposing the carbon negative with a screen is done away with and only a plain, unscreened print needs to be used. The multiplicity of V grains provides a strong combined grain which will cause a very fine shading 1n tones and tints to result in final prints. The etching acid will eat more slowly through this combined print so that the results desired will be obtained. A printing surface is produced which is even and deep and possesses. good and sufiicient depths and clean, open, -.fine, and easy printing qualities. Moreover, the so-called devils or little spots formed in single grain printing are avoided by this multiple grain process. It will, therefore, be apparent that the objects of the invention have been achieved.

I claim:

1. The process of making grain etchings comprising depositing a plurality of grains on a metal printing roll on both sides of a carbon print, and then etching the printing surface.

2. The process of making grain etchings comprising depositing a plurality of grains of different degrees of quality on a printing surface on both sides of a carbon print,

and then etchingithei printing: surface.

3. The processor" making grain etchings comprising depositing a plurality of grains, including a screened carbon print, on a printing surface in conjunction with an unscreened carbon print, and "then etchingthe print oversaid grain and. depositing another grain over said carbonpri'n't, and then etching the printing surface.

6. The process. of making grain etchings comprising depositing a. grain on aprinting surface, positioningan 'unscreened' carbon print over said grain, depositing a number ofgrains over said carbon print including a screened carbon print, and then etching the printing surface.

7. The process, of making grainetchings comprising depositing a grain ona printed surface, positioning an unscreened carbon print over said grain, depositing a second grain on the print, placing a screened carbon print over said second grain, and then etchingthe printing-v'surtace 8. The processo'fmaking grain etchings comprising depositing a grain on a printing surface, transferring an unscreened carbon print over the first grain, soaking and stripping' ofi the paper backing and. drying-the print,depositing, a second grain on the print and drying it, placing another carbon print which has been printed overa, fine grained screen position over the above mentioned print, soaking and stripping ofl thepaper, drying the printing surface, and then etching it.

'9. The process of making grain etchings comprising depositing a grain by spraying on a copper r011, transferring an unscreened carbon print over the first grain, soaking and stripping ofi'the paper backing, and

drying/the print, depositing a second grain of gum solution onthe print and drying; it, placing another carbon'pri-nt Which has been printed over a fine grained screen in position overthe above mentioned print, soaking and stripping on the paper, drying the roll, and then etching it.

In testimony that I claim the foregoing,

'I have hereunto-set my hand this 11th day of February, 1921.

CHARLES 'W. "SAALBURG. 

